Apterocyclus palmatus Van Dyke, 1921

Paulsen, M. J. & Hawks, David C., 2014, A review of the primary types of the Hawaiian stag beetle genus Apterocyclus Waterhouse (Coleoptera, Lucanidae, Lucaninae), with the description of a new species, ZooKeys 433, pp. 77-88 : 82-83

Taxon classification Animalia Coleoptera Lucanidae

Apterocyclus palmatus Van Dyke, 1921 Figs 7, 15, 20

Apterocyclus palmatus Van Dyke, 1921: 47, new status. Type material: Holotype male (CASC) labeled: a) handwritten "Kauai I. / Hawii (sic) / Alt. 4000 ft. / V-3-1919"; b) "Van Dyke / Collection"; c) handwritten "Apterocyclus / honoluluensis / var. palmatus / Van Dyke / Type"; d) "California Academy / of Sciences / Type / No. [3316]". One male paratype (CASC) labeled as holotype a, b, c [but with ‘Paratype’]. One male paratype (BPBM) labeled a) "[4000 ft] Kauai / [4/28 - 19 Nº5]”; b) "J. A. Kusche / Coll"; c) "[dissected / 10.X.21] / W.M. Giffard / [ Nº 5]"; d) handwritten "Apterocyclus / honoluluensis / var. palmatus / Van Dyke / Paratype"; e) on red paper "No. 24642 / Hawaiian Coll. / BISHOP Museum". One male paratype (BPBM) labeled a) "[4000 ft] Kauai / [4/28 - 19 Nº5]”; b) "J. A. Kusche / Coll"; c) handwritten "Apterocyclus / honoluluensis / var. palmatus / Van Dyke / Paratype"; d) on red paper "No. 24643 / Hawaiian Coll. / BISHOP Museum". One male paratype (BPBM) labeled a) handwritten "Kauai I. / Hawii (sic) / Alt. 4000 ft. / V-3-1919"; b) handwritten "Apterocyclus / honoluluensis / var. palmatus / Van Dyke / Paratype"; c) handwritten "for / Mr. Giffard"; d) on red paper "No. 24644 / Hawaiian Coll. / BISHOP Museum".

Diagnosis.

The male mandibles are tusk-like, elongate, nearly twice as long as in any other species, and lack an internal tooth. Also diagnostic are the protibiae that are greatly, triangularly expanded at the apex (Fig. 7), and the projecting tridentate clypeus. The specimens studied are 22-23 mm in length.

Distribution.

The species locality is unknown; the only available data is that the specimens were collected at an elevation of 4000 feet on Kauai by Mr. Kusche in 1919.

Remarks.

Van Dyke (1922) examined five male specimens, and all were located. Female specimens are not known, and the species has not been collected recently. The clearest evidence of Van Dyke’s overly conservative approach to the genus is that he considered this taxon to be an infraspecific form of Apterocyclus honoluluensis ; it is arguably the most drastically distinct subspecies of stag beetle ever proposed.